package Leetcode第一期;

public class 二叉搜索树的最近公共祖先_68_2 {
    public class TreeNode {
        int val;
        TreeNode left;
        TreeNode right;

        TreeNode(int x) {
            val = x;
        }
    }

    public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {
        if(root==null||root==p||root==q){
            return root;
        }
        TreeNode left=lowestCommonAncestor(root.left,p,q);
        TreeNode right=lowestCommonAncestor(root.right,p,q);

        //左子树没找到
        if(left==null){
            return right;
        }
        //右子树没找到
        if(right==null){
            return left;
        }
        return root;

    }
}
